diff --git a/unix/syscall_aix.go b/unix/syscall_aix.go
index e2a30e88..2db1b51e 100644
--- a/unix/syscall_aix.go
+++ b/unix/syscall_aix.go
@@ -253,7 +253,7 @@ func sendmsgN(fd int, iov []Iovec, oob []byte, ptr unsafe.Pointer, salen _Sockle
 	var empty bool
 	if len(oob) > 0 {
 		// send at least one normal byte
-		empty := emptyIovecs(iov)
+		empty = emptyIovecs(iov)
 		if empty {
 			var iova [1]Iovec
 			iova[0].Base = &dummy
diff --git a/unix/syscall_bsd.go b/unix/syscall_bsd.go
index c437fc5d..eda42671 100644
--- a/unix/syscall_bsd.go
+++ b/unix/syscall_bsd.go
@@ -363,7 +363,7 @@ func sendmsgN(fd int, iov []Iovec, oob []byte, ptr unsafe.Pointer, salen _Sockle
 	var empty bool
 	if len(oob) > 0 {
 		// send at least one normal byte
-		empty := emptyIovecs(iov)
+		empty = emptyIovecs(iov)
 		if empty {
 			var iova [1]Iovec
 			iova[0].Base = &dummy
diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
index 5e4a94f7..ecb0f27f 100644
--- a/unix/syscall_linux.go
+++ b/unix/syscall_linux.go
@@ -1541,7 +1541,7 @@ func sendmsgN(fd int, iov []Iovec, oob []byte, ptr unsafe.Pointer, salen _Sockle
 	var dummy byte
 	var empty bool
 	if len(oob) > 0 {
-		empty := emptyIovecs(iov)
+		empty = emptyIovecs(iov)
 		if empty {
 			var sockType int
 			sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)